1. Field of the Invention
The present invention relates to electrical wiring products and manufacture thereof. More particularly, the present invention relates to apparatus for separating and orienting conductors from a bundled array into a planar array, the process of using such apparatus, and the products of such a process.
2. Description of Related Art
Mass termination, insulation displacement connectors have come into increasing commercial prominence because of the significant savings in time and labor they offer compared to stripping and individually terminating each conductor. A form of conductors that has come to be widely used with such connectors is flat cable. Flat cable comprises conductors running parallel and spaced, at least at some point, to match the spacing of terminal elements in the connector. Flat cable also generally comprises a layer of insulation that acts to hold the conductors in place.
A type of flat cable that has become widely used in applications that require insulation displacement contacts (IDC) termination as well as mass termination in circuit board requirements is twisted flat ribbon cable. Twisted flat ribbon cable, as is well known to those skilled in the art, includes twisted pairs of wires having straight wire portions where the wires are disposed in a spaced, parallel relationship to allow connection to a connector. Twisted flat ribbon cable is presently manufactured with two inch, untwisted, flat portions every eighteen inches. Thus, as conveniently made and as is readily available, twisted flat ribbon cable can only be mass terminated at eighteen inch increments. Although it is possible to special order twisted flat ribbon cable of a nonstandard length, such special ordering is generally cost prohibitive unless an extremely large volume of nonstandard cable is ordered. Therefore, in all but very unusual situations, twisted pair flat cable is used in eighteen inch length increments.
Needless to say, being forced to use a popular cable in only certain lengths frequently results in waste and needless expense. For example, in a certain situation a twenty four inch length of twisted pair flat ribbon cable may be needed. As the cable may only be terminated in eighteen inch increments, unfortunately however, a thirty-six inch length of cable (i.e., two eighteen inch long portions) must be used. This results in twelve inches of wasted cable per use. In addition to adding unnecessary cost to units, such waste also results in bunching of excess cable (e.g., within a housing) that is unsightly at best, and possibly hazardous.
Further with respect to background art relating to the present invention, it should be appreciated that while flat cables, such as twisted flat ribbon cable, offer many advantages with respect to efficiency in termination, they present difficulties during routing. Comparing flat ribbon cable to round cable, for example, the flat ribbon cable has certain dimensions larger than comparable round cables. Such larger dimensions can make flat ribbon cable less susceptible than round cable to routing in certain situations, e.g., through conduits. Additionally, flat ribbon cable is somewhat less flexible than comparable round cable, insofar as it resists bending in non-orthogonal directions.
There are a number of patents including teachings pertinent to the general background of the present invention. These patents include U.S. Pat. No. 4,125,137 to Shatto, Jr., U.S. Pat. No. 3,936,933 to Folk et al., U.S. Pat. No. 4,642,874 to Litehizer, Jr., U.S. Pat. No. 4,767,891 to Biegon et al., and U.S. Pat. No. 4,486,253 to Gonia. Each of these patents is discussed briefly below.
U.S. Pat. No. 4,125,137 to Shatto, Jr. is directed to an apparatus for locating wires in a predetermined co-planar relationship to each other. Shatto, Jr. shows a template plate with a plurality of wire-receiving recesses 26, FIG. 1, and a roller 44 for pressing a plurality of wires 2, FIG. 2, in a predetermined spaced apart, co-planar relationship.
U.S. Pat. No. 3,936,933 to Folk et al. is directed to a method for positioning leading portions of individual wires of a plurality of wires in spaced-apart relationships with respect to each other and a template utilized in accomplishing the same. Folk et al. shows a planar grooved template 12, FIG. 1, used with a compressive force applying roller element 24, for positioning the leading portion L of a plurality of wires W in a spaced-apart relationship in preparation for the application of an electrical connecting device using a suitable applicator mechanism A.
U.S. Pat. No. 4,642,874 to Litehizer, Jr. is directed to a hand-held tool for wire insertion. Litehizer, Jr. shows a tooth indexing cartridge 100, FIG. 1, used with a tool assembly for inserting a plurality of conductors in a connector having a plurality of terminals.
U.S. Pat. No. 4,767,891 to Biegon et al. is directed to a mass terminable flat cable and cable assembly incorporating the cable. Biegon et al. show a cable section 70, FIG. 7, comprised of a plurality of loose twisted pairs of conductors 26A. At section 68, FIG. 4, the plurality of conductors 26A are held in regularly-spaced, parallel relationship by a carrier film 24A by means of the attachment layer 44A being fused with conductor jackets.
U.S. Pat. No. 4,486,253 to Gonia is directed to a method of making a multiconductor cable assembly. Gonia shows individual insulated conductors 22, 24, 26, 28 and 30, FIG. 4, bound in a compact profile in an intermediate portion 14, FIG. 1, and also at an end portion 18 in which the individual insulated conductors are not secured together. The conductors 22, 24, 26, 28 and 30, FIG. 1, are also shown arranged and bonded together in a side by side contiguous relationship along a portion of their mutual lengths at portion 12. The conductors are bonded together using a jig 42, FIG. 5.
In addition to the above-identified and described patents, there are a multitude of other patents and teachings relating to round and flat cables, apparatus for making such cables, and the processes used by the various apparatus in making such cables. Notwithstanding the voluminous teachings of the prior art, there is nowhere disclosed or suggested a simple, relatively inexpensive apparatus for quickly and easily producing wire perfectly suitable for any individual IDC mass termination application. This is a shortcoming and deficiency of the prior art. Further, related shortcomings and deficiencies of the prior art relate to the absence of cables manufactured by such a simple, relatively inexpensive apparatus and to the absence of teachings of a process effected by such an apparatus.